Boeing RB-52B/B-52B Stratofortress

Last revised June 30, 2000

The B-52B was the first truly operational version of the
Stratofortress. The B-52B was outwardly identical to the B-52A, but
featured an enhanced reconnaissance capability and was fitted with a
bombing/navigation system. A total of 50 were built, with 23 being
pure bomber B-52Bs and 27 being dual-capable reconnaissance/bomber
RB-52Bs. All of them were built at Seattle.

Letter Contract AF33(038)-21096 of February 1951 originally specified
13 B-52As but was changed on June 9, 1952 to include only 3 B-52As,
with the remainder to be delivered as B-52Bs. Another seven aircraft
were added to the contract at this time. As it turned out, all 17 of
these aircraft were actually completed as RB-52Bs. Serials were
52-0004/0013 and 52-8710/8716

Further B-52Bs were ordered later. Letter Contract AF33(600)-22119
was initially drawn up in September of 1952 and formally signed on
April 15, 1953. The contract called for 43 RB-52Bs. In April 1954,
the contract was amended and the number of RB-52Bs was cut to 33, with
the remaining ten machines to be completed as B-52Cs. As it turned
out, only ten of these aircraft were actually built as RB-52Bs, with
the rest being delivered as B-52Bs. Serials were 53-0366/0398.

The RB-52B had been the result of an earlier disagreement among Air
Force officers about what the true role of the B-52 should be--a pure
bomber or a pure reconnaissance aircraft. Although bearing an R
prefix, the RB-52B could be reconfigured in a matter of hours for
either a reconnaissance or a bombardment mission. The RB-52Bs carried
out its reconnaissance mission via a two-man pressurized capsule
installed in the bomb bay which could perform electronic
countermeasures or photographic reconnaissance work. Downward-firing
ejector seats were provided for the crew in the case of an inflight
emergency. Equipment inside the capsule could be optimized for
different types of intelligence-gathering missions and included
long-focal length and panoramic camers, plus photoflash bombs, mapping
radars, receivers, pulse analyzers and recorders. For search
operations, the pod had one AN/APR-14 low-frequency radar receiver and
two AN/APR-9 high-frequency radar receivers. Each station had two
AN/APA-11A pulse analyzers. The station also had three AN/ARR-88
panoramic receivers and all electronic data was recorded on an
AN/ANQ-1A wire recorder. Photographic equipment could include 4 K-38
cameras at the multi-camera station plus one T-11 or K-36 at the
vertical camera station. The pod could also carry three T-11
cartographic cameras. The reconfiguring of the aircraft was a fairly
straightforward process and the pod could usually be installed in
about four hours. Although the pods were retained in USAF inventory, these
pods were never actually employed operationally.

At the beginning, the engines of the B-52B/RB-52B were J57-P-1W, -1WA
or -1WB turbojets with water injection, the same engines which had
powered the B-52A. These were rated at 10,000 lb.s.t. dry and 11,000
lb.s.t. with water injection. About half of the B-52B/RB-52Bs were
delivered with these engines. In the meantime, there were attempts to
correct problems which had been encountered with the water injection
system. These efforts were expected to lead to the J57-P-9W engine
with titanium compressor blades. Unfortunately, problems with the
manufacture of the blades forced a return to steel blades in the
J57-P-29W and J57-P-29WA engines which were installed in the bulk of
the remaining B-52B/RB-52Bs. The -29W was rated at 10,500 lb.s.t dry
and 11,000 lb.s.t wet. The -29WA had twice the water flow rate as the
-29W, and had a 12,100 lb.s.t wet rating. The problems with the
titanium blades were finally overcome in the summer of 1956, which led
to the J57-P-19W version, which was installed in the final five
aircraft delivered.

The first B-52B took off on its maiden flight on January 25, 1955.
The first B-52B (52-8711) was delivered to the 93rd Bombardment Wing
at Castle AFB in California on June 29, 1955. Over the next few
months, the 93rd BW traded in its B-47s for B-52Bs, and changed its
name to the 93rd Bombardment Wing (Heavy). The 93rd BW was declared
combat ready on March 12, 1956, but its primary mission was the
training of future B-52 crews. The initial teething troubles with the
B-52 were not nearly as severe as those encountered with the early
B-47. However there were difficulties with the fuel system, imperfect
water injection pumps, faulty alternators, and especially with
deficient bombing and fire control systems.

The B-52B had originally been intended to carry the MA-2
bombing/navigation system, which combined an optical bombsight, a
radar presentation of target, and an automatic computer, together with
radar modifications designed for use in a high-speed aircraft.
However, the development of this package had been delayed.
Consequently, SAC had decided to equip some of the early production
B-52 aircraft with the Sperry K-3A system that was used by the B-36.
Unfortunately, at heights of 45,000 feet where the B-52B typically
operated, the K-3A system was found to be almost totally
ineffective--poor resolution qualities and a loss of definition made
it almost impossible to identify targets with any degree of certainty.
The Philco Corporation developed a temporary fix in which power output
was increased by about 50 percent, but this was not really much of a
solution and things really did not improve very much until the IBM
MA-6A system was finally available during the latter stages of the
B-model production run.

There were also problems experienced with the fire control system for
the tail-mounted defensive armament. Nine of the first ten RB-52Bs
(52-004/008 and 52-010/013 used a A-3A fire control system which
operated a quartet of 0.50-inch machine guns. However, one early
RB-52B (52-0009) was fitted with the alternative MD-5 fire control
system which incorporated a pair of M24A-1 20-mm cannon. This system
was adopted as standard equipment on the remaining 17 RB-52Bs and 16
B-52Bs (52-8710/8716 and 53-0366/0391). However, the new system
proved to offer no real improvement, and the last seven B-52Bs
reverted to the original system of four machine guns with a supposedly
improved A-3A fire control system. However, in reality, many of the
problems remained.

The original electrical system of the B-52 consisted of four air
turbine-driven 60 KVA alternators furnishing 200/115 volt three-phase
400 cycle alternating current. The first fatal B-52 crash in February
1956 was blamed on a faulty alternator. This caused the immediate
grounding of 20 B-52Bs and the halting in delivery of further B-52Bs
while the problem was addressed. In mid-May, deliveries were resumed,
but the alternator problem later reappeared.

In July 1956, there was another temporary grounding of the B-52B
fleet, this time because of fuel system and hydraulic pack
deficiencies. Although this grounding did not last long, the 93rd
BW's training program was adversely affected, and by mid-year there
were still no combat-ready B-52 crews.

The last B-52B was delivered in August of 1956. The B-models remained in service
into the mid-1960s when they were traded in for more modern B-52s.

A program known as Sunflower brought 7 early B-52Bs up to B-52C
standards. B-52Bs also went through many other modifications in
subsequent programs such as Harvest Moon, Blue Band, and
Quickclip, which were initially intended for the benefit of
subsequent B-52 models.

RB-52B serial number 52-008 was modified for use as a carrier aircraft for the X-15 and Lifting Body
flight research programs, and was redesignated NB-52B.